The FBI on Tuesday raided a Washington mansion linked to the billionaire Russian oligarch Oleg Deripaska, as part of what media reports described as a “court-authorised search”. Agents could be seen entering the neoclassical property located in the north-west of the US capital and standing guard outside. They sealed off the driveway with yellow tape. It said: “Crime scene – do not enter.” It was not immediately clear why the search had taken place. An FBI spokesperson said “law enforcement activity” was occurring, but declined to elaborate, according to NBC News. The specific reason for sealing off and searching the mansion was not immediately clear, and the FBI spokesperson did not provide details. A representative for Deripaska said the house – and a separate address – belonged to relatives of the oligarch. The raid appears to be the latest setback for Deripaska, who has sought to have his name removed from a US sanctions list. In June, a judge at a district court in Washington rejected a lawsuit he had filed against the US treasury department, which sanctioned him in 2018. Deripaska has made no secret of his support for the president, Vladimir Putin, and has declared he has no interest separate from those of the Russian state. He has also travelled on a Russian diplomatic passport, including during visits to the US. The treasury department imposed sanctions in response to Russia’s sweeping campaign in 2016 to meddle in the US election, and to various cyber-attacks. It said Deripaska had acted “on behalf of … a senior Russian government official” – code for Putin – and had claimed to represent the Kremlin in other countries. The treasury said then: “Deripaska has been investigated for money laundering, and has been accused of threatening the lives of business rivals, illegally wiretapping a government official, and taking part in extortion and racketeering.” The US also sanctioned Deripaska’s companies, including the aluminium giant United Company Rusal, and Basic Element. Deripaska vehemently denies wrongdoing. In his writ, he said the US move had effectively destroyed his wealth, reputation and hard-earned global assets. Rusal was removed from the sanctions blacklist after Deripaska reduced his majority stake and gave up control of Rusal’s holding company, EN+. Deripaska’s wealth is currently estimated at $4.9bn, according to Forbes magazine.